<template>
  <div id="app">
    <div class="container">
      <!-- 顶部搜索框模块 -->
      <div class="form-group">
        <div class="input-group">
          <h4>品牌管理</h4>
        </div>
      </div>

      <!-- 数据表格 -->
      <table class="table table-bordered table-hover mt-2">
        <thead>
          <tr>
            <th>编号</th>
            <th>资产名称</th>
            <th>价格</th>
            <th>创建时间</th>
            <th>操作</th>
          </tr>
        </thead>
        <tbody>
          <tr v-for="(item,idx) in list" :key="item.id">
            <td>{{item.id}}</td>
            <td>{{item.name}}</td>

            <!-- 如果价格超过100，就有red这个类 -->
            <td :class="{red:item.price>100}">{{item.price}}</td>
            <td>{{FormDate(item.time)}}</td>
            <td @click="list.splice(idx,1)"><a href="#" >删除</a></td>
          </tr>
        </tbody>
        <tfoot >
          <tr v-if="list.length===0">
            <td colspan="5" style="text-align: center">暂无数据</td>
          </tr>
        </tfoot>
        <tfoot >
          <tr>
            <td colspan="5" style="text-align: center">共计:{{sum}} 平均值{{avg}}</td>
          </tr>
        </tfoot>
      </table>

      <!-- 添加资产 -->
      <form class="form-inline">
        <div class="form-group">
          <div class="input-group">
            <input
              v-model.trim="goods.name"
              type="text"
              class="form-control"
              placeholder="资产名称"
            />
          </div>
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <div class="form-group">
          <div class="input-group">
            <input
              v-model.number="goods.price"
              type="text"
              class="form-control"
              placeholder="价格"
            />
          </div>
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <!-- 阻止表单提交 -->
        <button class="btn btn-primary" @click.prevent="add">添加资产</button>
      </form>
    </div>
  </div>
</template>

<script>
import "bootstrap/dist/css/bootstrap.css"
import moment from 'moment'
export default {
  data() {
    return {
      goods:{
        name: "", // 名称
        price: 0, // 价格
      },
     
      list:JSON.parse(localStorage.getItem('list')) || [
        { id: 100, name: "外套", price: 199, time: new Date('2010-08-12')},
        { id: 101, name: "裤子", price: 34, time: new Date('2013-09-01') },
        { id: 102, name: "鞋", price: 25.4, time: new Date('2018-11-22') },
        { id: 103, name: "头发", price: 19900, time: new Date('2020-12-12') }
      ],
    };
  },
  methods: {
    FormDate(time){
    return  moment(time).format('YYYY-MM-DD')
    },
    add(){
      // 解构
      const {goods,list} = this
      // 非空判断
      if(goods.name===''||goods.price==='')
      return
        // 1.添加资产
     list.push({
       id:list.length> 0 ? list[list.length-1].id+1:1,
       name:goods.name,
       price:goods.price,
       time:new Date
     })
    // 2.清空表单
     goods.name=""
     goods.price=""
    }

  },

  computed:{
    sum(){
    return  this.list.reduce((sum,item)=>sum+item.price,0)
    },
    avg(){
     return this.sum/this.list.length
    }
  },
  watch:{
    list:{
      deep:true,
      handler(newVal){
        return  localStorage.setItem('list',JSON.stringify(newVal))
      }
    }
  }

};
</script>

<style >
.red{
  color: red;
}
</style>